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CN-122013564-A - One-bath dyeing auxiliary agent for polyester-cotton blended fabric and preparation method thereof

CN122013564ACN 122013564 ACN122013564 ACN 122013564ACN-122013564-A

Abstract

The invention discloses a one-bath dyeing auxiliary agent for polyester-cotton blended fabrics and a preparation method thereof. The auxiliary agent is prepared by partially hydrophobizing a terminal primary amine group of a 2.0-generation polyamide-amine type dendritic polymer and hyperbranched polyethyleneimine with specific molecular weight and branching degree and quaternizing the rest, wherein the molar ratio of the hydrophobized terminal to the quaternary ammonium salt terminal is 1:9-1. The preparation method comprises the steps of carrying out controllable amidation reaction under the protection of inert gas to introduce a C12-C18 alkyl hydrophobic chain, then carrying out complete quaternization reaction to introduce a trimethyl quaternary ammonium iodized salt group, and finally obtaining the product through dialysis purification and impurity residue detection. Through simultaneously constructing the hydrophobic and quaternary ammonium salt terminal on the multi-branched polymer skeleton, the auxiliary agent realizes the synergistic effect of dispersion isolation of disperse dye and efficient dyeing promotion and hydrolysis inhibition of reactive dye, thereby improving dye uptake and color fastness in polyester-cotton bath dyeing and reducing the consumption of inorganic salt.

Inventors

  • YANG XIANGCHEN
  • ZOU TONGCHUN
  • DENG LIJUN
  • XU DA
  • Sheng Congan
  • FENG JINHUI

Assignees

  • 绵阳佳利德纺织科技有限公司

Dates

Publication Date
20260512
Application Date
20260324

Claims (7)

  1. 1. A one-bath dyeing auxiliary agent for polyester-cotton blended fabrics is characterized by being prepared by carrying out terminal chemical modification on a polymer framework with at least 8 terminal primary amine groups, wherein the polymer framework is selected from one of 2.0-generation polyamide-amine type dendritic polymers and hyperbranched polyethyleneimines, wherein part of terminal primary amine groups of the polymer are grafted with C12-C18 alkyl groups through amidation reaction to form a hydrophobization terminal, the residual terminal primary amine groups are converted into trimethyl quaternary ammonium iodide salt through reaction with methyl iodide to form quaternary ammonium salt terminal, and the molar ratio of the hydrophobization terminal to the quaternary ammonium salt terminal is 1:9-1:1.
  2. 2. The dyeing auxiliary according to claim 1, wherein the auxiliary takes a 2.0-generation polyamide-amine type dendritic polymer as a framework, the hydrophobization terminal has a structure represented by a formula (A-1): CH 2 -CH 2 -NH-CO-R 1 (A-1), the quaternary ammonium salt terminal has a structure represented by a formula (B-1): CH 2 -CH 2 -N + (CH 3 ) 3 I - (B-1), and R 1 is a C12-C18 alkyl group.
  3. 3. Dyeing auxiliary according to claim 1, characterized in that the auxiliary has a hyperbranched polyethyleneimine as skeleton, has a weight-average molecular weight Mw of 5000 to 20000 daltons and a branching degree DB of 0.4 to 0.8, calculated by means of a 1 H-NMR spectrum in DMSO-D6 as solvent according to formula DB= (D+T)/(D+L+T), wherein D, L, T respectively represents the relative number of hydrogen atoms of the branching unit, the linear unit and the terminal unit in the spectrum, the hydrophobicized terminal has a structure of formula (A-2) CH 2 -CH 2 -NH-CO-R 1 (A-2) and the quaternary ammonium salt terminal has a structure of formula (B-2) CH 2 -CH 2 -N + (CH 3 ) 3 I - (B-2), wherein R 1 is C12-C18 alkyl.
  4. 4. A process for the preparation of a dyeing auxiliary according to any one of claims 1 to 3, comprising the steps of: S1, providing a precursor polymer, namely selecting 2.0-generation polyamide-amine type dendritic polymer and selecting one of hyperbranched polyethyleneimine with weight average molecular weight Mw of 5000-20000 daltons and branching degree DB of 0.4-0.8; S2, partial terminal hydrophobization modification, namely dissolving the precursor polymer in anhydrous N, N-dimethylformamide, adding triethylamine as an acid binding agent, then adding C12-C18 alkyl acyl chloride containing acyl chloride groups, controlling the molar feed ratio of the acyl chloride compound to the terminal primary amino groups of the precursor polymer to be 0.1:1-0.5:1, stirring and reacting for 4-8 hours under the reaction condition of continuously introducing dry nitrogen at 20-40 ℃ to obtain an intermediate, monitoring the reaction process through sampling by 1 H-NMR spectrum, calculating and controlling the hydrophobization modification degree to be 10-50% according to the proportion of the integral area of N-H proton peaks of amide bonds generated after the reaction to the integral area of the proton peaks of the total terminal primary amino groups measured before the reaction; S3, completely quaternizing and modifying the residual tail end, namely adding excessive methyl iodide into the intermediate reaction mixture obtained in the step S2, controlling the molar ratio of the methyl iodide to the residual tail end primary amino in the intermediate to be 3.0:1-5.0:1, and continuously stirring and reacting for 36-72 hours under the conditions of 60-80 ℃ and light shielding and condensation reflux cooled by using an ice water bath, wherein the reaction end point is judged by sampling through 1 H-NMR spectrum, and when the tail end primary amino proton peak completely disappears, the reaction is judged to be complete, so as to obtain a reaction crude product; S4, purifying and detecting, namely cooling the reaction crude product to room temperature, transferring the reaction crude product to a dialysis bag with the molecular weight cut-off of 1000 daltons, dialyzing the reaction crude product in flowing deionized water with continuous stirring for 48-72 hours, taking dialysis inner liquid, detecting methyl iodide residues by gas chromatography, detecting triethylamine hydrochloride residues by ion chromatography to ensure that the mass fractions of the reaction inner liquid and the dialysis inner liquid are lower than 0.1%, and then freeze-drying the solution to obtain the dyeing auxiliary agent.
  5. 5. The method according to claim 4, wherein in step S2, the acyl chloride-containing C12-C18 alkyl chloride is one selected from the group consisting of myristoyl chloride C 13 H 27 COCl, palmitoyl chloride C 15 H 31 COCl and stearoyl chloride C 17 H 35 COCl.
  6. 6. The method according to claim 4, wherein the degree of modification by hydrophobization in step S2 is 15% to 40%.
  7. 7. The method according to claim 4, wherein in step S3, the molar ratio of methyl iodide to remaining terminal primary amine groups in the intermediate is 4.0:1.

Description

One-bath dyeing auxiliary agent for polyester-cotton blended fabric and preparation method thereof Technical Field The invention relates to the technical field of textile printing and dyeing, in particular to a one-bath dyeing auxiliary agent for polyester-cotton blended fabric and a preparation method thereof. Background The polyester-cotton blended fabric has the advantages of high strength, wrinkle resistance, shape retention, moisture absorption, ventilation, softness, comfort and the like of polyester fibers, and occupies an important market share in the fields of clothing, home textile and the like. However, the physical and chemical properties of the two fibers of the terylene and the cotton are obviously different, so that dyeing and processing of the terylene and the cotton become a long-standing technical problem in the textile printing and dyeing industry. The traditional polyester-cotton blended fabric is mainly dyed by a two-bath two-step method, namely, the polyester component is dyed by using a disperse dye under neutral to weak acid and high temperature conditions, and the cotton component is dyed by using a reactive dye under alkaline and medium temperature conditions after reduction cleaning. The process can ensure that two types of dyes are fixed under the better condition to obtain higher color fastness, but has the outstanding problems of long process flow, huge water, electricity and steam energy consumption, high equipment occupancy rate, large wastewater discharge, complex components and the like, and is seriously different from the current development trend of green, low-carbon and high-efficiency textile manufacturing. In order to simplify the flow and reduce the cost, the industry develops a one-bath dyeing process, and aims to simultaneously finish dyeing of terylene and cotton fibers in the same dyeing bath. According to the dyeing stage division, the one-bath method can be divided into a one-bath two-step method and a one-bath one-step method. Among them, the one-bath one-step method becomes a research hot spot due to the shortest flow and highest efficiency potential. However, implementation faces fundamental challenges brought by inherent contradiction between polyester and cotton dyeing mechanisms: The dyeing temperature and the pH condition conflict that the dyeing of the disperse dye on the polyester needs high temperature, high pressure and weak acid environment to realize the swelling and the diffusion of the dye, and the fixation reaction of the reactive dye and the cotton fiber needs to be carried out at relatively low temperature and strong alkaline environment to promote the reaction of the dye and the hydroxyl of the fiber and inhibit the hydrolysis of the dye. It is difficult to reconcile these two distinct process requirements in one bath. The mutual interference among dyes is that under the condition of high Wen Ruosuan property, the reactive dye is easy to be hydrolyzed and deactivated, so that the dyeing rate and the fixation rate are suddenly reduced, and meanwhile, the nonionic disperse dye is easy to be aggregated in a dye bath and is stained on the surface of cotton fiber, so that the dyeing quality is seriously affected due to dyeing of cotton components, dark color and light and reduced wet processing fastness. High salt consumption and environmental pollution reactive dye dyeing generally requires a large amount of inorganic salt as an accelerating agent to overcome negative charge repulsion of the cotton fiber surface. The method not only increases the production cost, but also causes extremely high salinity and chemical oxygen demand in the dyeing wastewater, and has large subsequent treatment difficulty and heavy environmental burden. In order to cope with the challenges, the prior art is mainly improved from two directions, namely, developing novel dyes such as alkali-resistant disperse dyes and high-temperature reactive dyes to widen a shared process window, and designing special dyeing auxiliary agents to isolate the two dyes, reduce dyeing temperature and reduce salt consumption. In the latter, the microcapsule technique attempts to avoid contact with reactive dyes and cotton fibers at the early stages of dyeing by coating the disperse dyes, followed by release at high temperatures. However, these methods have significant limitations in that the novel dye system has a narrow selection range and high cost, the microcapsule preparation process is complex, the batch stability is difficult to control, the capsule wall material may introduce new environmental problems, and the effect on how to solve the problems of hydrolysis and dyeing promotion of the reactive dye simultaneously is limited. In recent years, physical field assisted dyeing technology has also been introduced, and the dyeing temperature can be reduced to a certain extent by promoting dye dispersion and fiber penetration through cavitation effect. However, the technology relies on specia